package com.cawis.handler;

import com.alibaba.csp.sentinel.adapter.gateway.sc.SentinelGatewayFilter;
import com.alibaba.csp.sentinel.adapter.spring.webmvc.callback.BlockExceptionHandler;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import com.alibaba.csp.sentinel.slots.block.authority.AuthorityException;
import com.alibaba.csp.sentinel.slots.block.degrade.DegradeException;
import com.alibaba.csp.sentinel.slots.block.flow.FlowException;
import com.alibaba.csp.sentinel.slots.block.flow.param.ParamFlowException;
import com.alibaba.fastjson.JSON;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.annotation.Order;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.Hashtable;
import java.util.Map;

@Configuration
public class SentinelExceptionHandler implements BlockExceptionHandler {

    @Override
    public void handle(HttpServletRequest request, HttpServletResponse response, BlockException e) throws Exception {
        Map data = new Hashtable();
        String msg = "未知异常";
        int status = 429;
        if (e instanceof FlowException) {
            msg = "请求被限流了";
        } else if (e instanceof ParamFlowException) {
            msg = "请求被热点参数限流";
        } else if (e instanceof DegradeException) {
            msg = "请求被降级了";
        } else if (e instanceof AuthorityException) {
            msg = "没有权限访问";
            status = 401;
        }
        response.setContentType("application/json;charset=utf-8");
        response.setStatus(status);
        data.put("data", msg);
        data.put("status", status);
        response.getWriter().println(JSON.toJSONString(data));
    }

    @Bean
    @Order(0)
    public GlobalFilter sentinelGatewayFilter() {
        return new SentinelGatewayFilter();
    }

}
